2. Article 208(3)3 of the Civil Procedure Act of the applicable provisions of the Acts [the statutory interest rate under Article 3(1) of the Act on Special Cases Concerning the Promotion, etc. of Legal Proceedings may apply from the day following the day on which a written complaint demanding the performance of a monetary obligation or a document corresponding thereto is served on the obligor. Thus, if a creditor expands the claim, the extended amount of the claim can be applied to the interest rate under the said provision from the day following the day on which the written statement expanding the claim was served on the obligor (see, e.g., Supreme Court Decision 94Da56234, Feb. 17, 1995). As to KRW 100 million claimed in the initial complaint, the statutory interest rate of KRW 350,000,000,000 extended from April 11, 2018, which is the day following the day on which the written request for alteration of the claim was served on the obligor];